Characterization and Antifungal Potential of Green-Synthesized Copper Nanoparticles Using Waste Leaf Biomass

Abstract The synthesis of metal nanoparticles is of great interest among the research community due to their versatile physical, chemical and antimicrobial properties and myriads of applications. Researchers across the world employ various protocols to synthesize metallic nanoparticles. However, the synthesis of nanoparticles using biomaterials, i.e., green synthesis, has advantages over conventional methods because they use toxic reagents and produce harmful byproducts. In this study, plant leaf extracts rich in flavonoids, tannins, glycosides, and alkaloids obtained from four different species-neem, teak, senna and lantana-were used to synthesize copper nanoparticles from CuSO4 (0.1 M) solution. Plant extracts act as reducing, stabilizing, and capping agents simultaneously. Characterization via UV‒Vis spectroscopy, FE-SEM, EDXS, FT-IR, TGA and XRD as well as yield analysis was performed for the green synthesized CuNPs. The maximum yield was obtained from teak leaf extract followed by senna, lantana and neem. FE-SEM images revealed the shape and nano dimension of the CuNPs. The presence of CuNPs was also confirmed from the UV‒Vis spectra which showed a characteristic peak between 300 and 350 nm. The CuNPs were further analyzed through EDXS, FTIR, XRD and TGA which showed characteristic peak regions in the graph. Additionally, the antifungal potential of the CuNPs was tested using Corynespora cassiicola by the poison food technique. Overall, this study provides an insight into the importance of selecting suitable plant extracts for the production of CuNPs in a cost effective and environmentally friendly way.